ANODIZING AND COLORIZATION

Anodizing is a process that consists in formation of an aluminium oxide layer on surfaces of aluminium components and shaped sections. The anodized coating is firmly bonded with the surface of component and it can be given a desired colour. This coating also acts as a protective shell and prevents from penetration of ambient agents, even such aggressive and acid rains or seawater.

PROPERTIES OF ANODIZED COATINGS APPLIED ONTO ALUMINIUM

COATING COLOUR

Colour of the oxide coating formed on the aluminium depends on the grade of the base material that is determined by types and content of admixed alloy ingredients and conditions of the product manufacturing.

COLOURIZATION – BROAD SPECTRUM OF COLOURS

We carry out colourization of aluminium products by means of two methods, with regard to the base material and the desired final effect:

the most homogenous coatings can be achieved on materials that have been mechanically deformed or subjected to thermal homogenization,

purely colourless coatings can be achieved only in case when pure aluminium is the base material for anodizing.

Use of high-alloy materials as base metals makes the applied coatings more or less grey. Improper homogenization of alloys may lead to formation of stains and various discolorations on the metal surface.

Thickness of oxygen layers formed on the aluminium surface depends on the conditions of the anodizing process as well as on composition and structure of the base material. For low-alloy materials and workpieces made of pure aluminium the possible thickness of oxidized layers may vary from 5 to 25 m, depending on requirements of customers.

The hardness of coatings substantially depends on the parameters of the anodizing process. For conventional coatings the hardness ranges from 100 to 300 HV 0.05.

There is the rule that colourization is the most efficient for coating applied onto pure aluminium (1xxx) or low-alloy materials (5xxx, 6xxx). On the other hand, alloys with high content of copper (2xxx) or zinc (7xxx) are quite difficult for application of colours. Cast alloys with the content of silicon above 3% are not suitable for anodizing at all.

ELECTROCHEMICAL DYING

It is the method that enables formation of colours films with many shades of brown and the colour that imitates appearance of stainless steel. The colours achieved by means of the electrochemical process are very resistant to the effect of light. Films applied through the electrochemical process are perfectly suitable for outdoor applications due to their high insensitivity to ambient factors.

Available colours:

Light brown

Dark brown

Black

Light gold

Gold

Patina gold

Stainless steel (inox)

CHEMICAL DYING

Coatings subjected to colourization by means of chemical processes perfectly prove themselves in application where decorative properties are crucial factors. The applicability of coatings for outdoor applications depends on such factors as the base material, thickness of the applied film and the selected colour. One has to be aware that shades of final colours may differ for various grades of base aluminium.